Scientists propose liquid lunar telescope

Astronauts on the moon may one day pour themselves a liquid telescope to gaze at distant galaxies.

Scientists have proposed using a liquid compound to craft a giant disc-shaped mirror that would be capable of reflecting objects that are undetectable by other telescopes, according to a paper published this week in the journal Nature. With much less expense than transporting a solid mirror, the liquid would be carried in a drum and poured over a disc-shaped mesh that unfurls robotically, according the paper. Surface tension on the mesh would prevent the liquid from dripping through its small holes, according to the scientists.

A liquid mirror 3.7 meters in diameter at Laval University.
Guy Plante/Laval University

The result would be an optical-infrared telescope with a 66-foot to 328-foot aperture, which could reflect faint objects in dwarf or normal galaxies.

"We have shown how the moon is ideal (for) using liquid mirror technology to build a telescope much larger than we can affordably build in space," Pete Worden, director of NASA Ames Research Center, said in a statement.

"Such telescopes, perhaps 100 meters in diameter can see back to the early phases of the universe after the Big Bang," he said. Worden coauthored the paper.

The research, funded by the NASA Institute for Advanced Concepts, is designed to support the study of astronomy when NASA heads back to the moon, as part of an overall goal of the space agency.

According to the paper, the liquid compound includes ionic salts and layers of chromium and silver particles. In lab tests, the mirror's reflectiveness isn't yet sufficient, the scientists said, but it's only a "matter of technological improvement.

When might astronauts use a liquid mirror? The scientists predict the first lunar telescope will be built no earlier than 2020.